Deployable System with Flexible Membrane

ABSTRACT

An example system for extraterrestrial deployment of a flexible membrane surface includes a flexible membrane having a periphery and an interior. The flexible membrane is rolled about a roll axis into a cylindrical geometric shape in an undeployed state. A payload base has extendable radial booms, wherein the distal end of each extendable radial boom is attached to the periphery of the flexible membrane and the interior of the flexible membrane is free of attachment to the extendable radial booms. The payload base and the extendable radial booms are positioned to one side of the flexible membrane along the roll axis. The extendable radial booms are configured to extend orthogonally to the roll axis from the payload base to unroll the flexible membrane about the roll axis to form the flexible membrane surface in a deployed state, wherein the roll axis is substantially orthogonal to the flexible membrane surface.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of and claims benefit ofpriority to U.S. application Ser. No. 16/748,471, entitled “DeployableSystem with Flexible Membrane” and filed on Jan. 21, 2020, which claimsbenefit of priority to U.S. Provisional Application No. 62/794,385,entitled “Deployable System with Flexible Membrane” and filed on Jan.18, 2019, which is specifically incorporated by reference herein for allthat they disclose and teach.

BACKGROUND

One approach to providing a deployable system that can support a deviceor devices so as to realize a large aperture is to provide a number ofrigid, planar panels deployed along a single axis. Each rigid panelsupports a device, a portion of a device, or multiple devices.Typically, the devices are solar cells and/or radiofrequency antennas.However, other types of devices are also feasible. In the undeployedstate, the rigid panels and supported devices are stored as a stack ofpanels. When deployed, the rigid panels unstack along a single axis soas to form a substantially rigid, planar structure extended along theaxis.

SUMMARY

The described technology relates to a deployable system that is adaptedto deploy a flexible membrane or blanket, which can, in turn, support adevice or devices so as to realize a large aperture for the device ordevices. In some implementations, however, no devices are supported onthe flexible membrane.

The described technology provides a system for extraterrestrialdeployment of a flexible membrane surface including a flexible membranehaving a periphery and an interior. The flexible membrane is rolledabout a roll axis into a cylindrical geometric shape in an undeployedstate. A payload base has extendable radial booms, wherein the distalend of each extendable radial boom is attached to the periphery of theflexible membrane and the interior of the flexible membrane is free ofattachment to the extendable radial booms. The payload base and theextendable radial booms are positioned to one side of the flexiblemembrane along the roll axis. The extendable radial booms are configuredto extend orthogonally to the roll axis from the payload base to unrollthe flexible membrane about the roll axis to form the flexible membranesurface in a deployed state, wherein the roll axis is substantiallyorthogonal to the flexible membrane surface.

This summary is provided to introduce a selection of concepts in asimplified form that is further described below in the DetailedDescription. This summary is not intended to identify key features oressential features of the claimed subject matter, nor is it intended tobe used to limit the scope of the claimed subject matter.

Other implementations are also described and recited herein.

BRIEF DESCRIPTIONS OF THE DRAWINGS

FIG. 1 illustrates an example environment for use in deploying anexample deployable system in multiple phases.

FIGS. 2A-2C illustrate an example deployable system in an undeployedstate.

FIGS. 3A-3D illustrate an example flexible membrane with respect to alaunch restraint cage.

FIGS. 4A and 4B illustrate an example flexible membrane of a deployablesystem in a deployed state.

FIGS. 5A and 5B illustrate a payload base of an example deployablesystem.

FIG. 6 illustrates an example deployable system in a deployed state,including a payload base attached to a flexible membrane.

FIGS. 7A-7D illustrate four phases of deployment of a flexible membraneof an example deployable system in a perspective view from a first side.

FIGS. 8A-8C illustrate three phases of deployment of a flexible membraneof an example deployable system in a perspective view from a secondside.

FIG. 9 illustrates z-fold lines in an example flexible membrane having asemi-rigid support member at one end of the example flexible membrane.

FIG. 10 illustrates partially folded z-folds in an example flexiblemembrane having a semi-rigid support member at one end of the exampleflexible membrane.

FIGS. 11A-11B illustrate an example flexible membrane rolled about aroll axis into a cylindrical geometric shape of an undeployed state andhaving a small-radius loop positioned within the interior of thecylindrical geometric shape.

FIG. 12 illustrates a rolling and unrolling of an example flexiblemembrane about a roll axis between an undeployed state and a (partially)deployed state, wherein the flexible membrane forms a cylindricalgeometric shape with a small-radius loop positioned within the interiorof the cylindrical geometric shape.

FIG. 13 illustrates z-fold lines in an example flexible membrane havingsemi-rigid support members at opposite ends of the example flexiblemembrane.

FIGS. 14A-14B illustrate an example flexible membrane rolled about aroll axis into a cylindrical geometric shape of an undeployed state andhaving two small-radius loops positioned within the interior of thecylindrical geometric shape.

FIG. 15 illustrates a rolling and unrolling of an example flexiblemembrane about a roll axis (indicated by the dashed line “x” at thecenter of the roll) between an undeployed state and a (partially)deployed state, wherein the flexible membrane forms a cylindricalgeometric shape with two small-radius loops positioned within theinterior of the cylindrical geometric shape.

FIG. 16 illustrates a phase of z-folding operation on an exampleflexible membrane.

FIG. 17 illustrates another phase of z-folding operation on an exampleflexible membrane.

FIG. 18 illustrates yet another phase of z-folding operation on anexample flexible membrane.

FIG. 19 illustrates a phase of z-folding operation on an exampleflexible membrane.

FIG. 20 illustrates another phase of z-folding operation on an exampleflexible membrane.

FIG. 21 illustrates yet another phase of z-folding operation on anexample flexible membrane.

FIGS. 22A-22D illustrate panels of an example flexible membrane havingshear compliant connectors.

FIG. 23 illustrates example deployment operations for an exampledeployable system.

DETAILED DESCRIPTIONS

The described technology is directed to a deployable system thatemploys: (a) a flexible membrane to support the device or devices ofinterest in a deployed state so as to realize a large aperture and (b) adeployment system for transitioning the flexible membrane from anundeployed state to a deployed state. In some implementations, however,no devices are supported on the flexible membrane.

In one embodiment, the flexible membrane has flexibility such that themembrane can be folded/unrolled about at least two orthogonal axesassociated with the flexible membrane. These orthogonal axes arereferred to as the z-fold axis and the roll axis. Flexibility relativeto a z-fold axis allows the flexible membrane to be z-folded so as todefine two membrane panels separated by a fold junction. Flexibilityrelative to the roll axis allows a z-folded membrane to be rolled so asto form a structure having cylindrical geometric shape.

In one implementation, a flexible membrane is formed from multiplesemi-rigid panels mounted on a thin continuous flexible substrate fabricthat holds the semi-rigid panels together to form a continuousshear-compliant membrane. The thin continuous flexible substrate fabricmay be a single piece of fabric, or multiple pieces of fabric boundtogether to form a single flexible membrane of fabric-supportedsemi-rigid panels, when in both the undeployed state and the deployedstate. In another implementation, the multiple semi-rigid panelsthemselves are bound together by shear compliant connectors (independentof any thin continuous flexible substrate fabric) to form a continuousshear-compliant membrane of discrete semi-rigid panels. In thisimplementation, the panels are connected together using the shearcompliant connectors at the fold junctions between the panels to asingle flexible membrane of junction-connected semi-rigid panels, whenin both the undeployed state and the deployed state. In yet anotherimplementation, the devices themselves may be mounted directly on a thincontinuous flexible substrate fabric rather than on intermediatesemi-rigid panels.

Each panel has a periphery and an interior region within the periphery.For example, in an implementation including the shear compliantconnectors, the flexible membrane defines a series of attachment points(e.g., holes) in the interior regions of the semi-rigid panels along thepanel edges near where the z-folding occurs. The shear compliantconnectors are attached to these attachments points to bind adjacentsemi-rigid panels together at a fold junction and to reduce the shearingissue that occurs when a z-folded membrane is subsequently rolled. Inthis embodiment, the flexible membrane is still deemed to be continuous,although it consists of multiple discrete semi-rigid panels. Theinterior region is offset from the periphery by at least the distance toaccommodate an acceptable shear tolerance between two adjacent panelshaving the shear compliant connectors attached to positions in theinterior regions of the panels. (See, e.g., FIG. 22 for an illustrationof shear compliant connectors and acceptable shear tolerances.) Asdescribed herein, the term “shear compliant” refers to a flexible yetresilient connection between adjacent panels that allows the adjacentpanels to shift relative to each other while entering an undeployedstate (e.g., while the panels of the flexible membrane are rolled) andstill return to a re-aligned position in a deployed state (e.g., whilethe panels of the flexible membrane are unrolled).

Example thin continuous flexible substrate fabrics may include withoutlimitation plastic or plastic-like films, woven materials, latticestructures, or other flexible structures or combinations thereof. Panelsthat can be mounted on such a fabric or otherwise interconnected into acontinuous flexible membrane may include plastic or plastic-like films,woven materials, lattice structures, or other flexible structures orcombinations thereof.

FIG. 1 illustrates an example environment 100 for use in deploying anexample deployable system 102 in multiple phases. The exampleenvironment 100 includes the Earth 104 and the Sun 106. In the exampleenvironment, a launch vehicle 108 launches from the Earth 104, typicallywith multiple stages. For example, in one implementation, an enginestage is ignited at launch and burns through a powered ascent until itspropellants are exhausted. The engine stage is then extinguished, and apayload stage separates from the engine stage and is ignited. Thepayload is carried atop the payload stage into orbit.

In FIG. 1 , a payload stage 110 has separated from the engine stage (notshown). In the first phase showing the deployable system 102, payloadfairings 112, which can form a nose cone to protect a launch vehiclepayload against the dynamic pressure and aerodynamic heating duringlaunch through an atmosphere, are jettisoned, exposing the deployablesystem 102 to the space environment.

As shown in this first (undeployed) phase, the deployable system 102 isshown in an undeployed or stowed state, with a payload base 114 and aflexible membrane 116. The payload base 114 may include withoutlimitation a variety of different sub-systems, such as any combinationof navigation sub-systems, propulsion sub-systems, control sub-systems,communication sub-systems, power sub-systems, membrane-deployingsub-systems, and any other payload sub-systems. In this first phase, theflexible membrane 116 of the deployable system 102 is illustrated asstowed in a small-volume undeployed state relative to the deployed stateshown in a subsequent phase, typically contained in a launch restraintcage (not shown).

In one implementation, the flexible membrane 116 includes an array ormatrix of semi-rigid panels that support a device, a portion of adevice, or multiple devices (e.g., photovoltaic devices, radiofrequencydevices, optical devices). The semi-rigid panels are rollable, with someamount of resilience, such that the flexible membrane 116 can be rolledabout a roll axis. This resilience results in an expansive load on theflexible membrane 116 when in the undeployed (e.g., rolled) state, suchthat the rolled flexible membrane is biased toward unrolling if notconstrained, which presents a utility of the launch restraint cage.

In the next (deployed) phase, the deployable system 102 is shown in adeployed state in which the flexible membrane 116 has been expanded to alarger area relative to the size of the flexible membrane 116 in itsundeployed state and the size of the payload base 114. In theillustrated example, (extendable) radial booms 118 extend radiallyoutward from the payload base 114 to unfurl the flexible membrane 116from its undeployed state. Locations near the periphery region at theperimeter of the expanded form of the flexible membrane 116 are attachedto distal ends of the radial booms 118 (e.g., distal ends of the radialbooms 118 relative to the payload base 114). Accordingly, as the radialbooms 118 extend, the ends of the radial booms 118 push and/or pull tounroll and/or unfold the flexible membrane 116 from its undeployed stateto its deployed state. In addition, in at least one implementation,locations within the interior of the flexible membrane 116 are free fromattachment to the radial booms 118, so as to facilitate the unrollingand unfolding

A facing surface 120 of the payload base 114 faces the flexible membrane116 and is out-of-plane with the radial booms 118. Furthermore, theattachments between the periphery locations of the flexible membrane 116and the distal ends of the radial booms 118 are short enough to keep theexpanded surface of the flexible membrane 116 taut against or otherwisein contact with at least one portion of the facing surface 120 (e.g.,the edges of the facing surface 120) or a structural component connectedthereto. In this manner, the flexible membrane 116 is tensioned againstor otherwise in contact with the payload base 114 (e.g., to reduce oreliminate movement of the flexible membrane 116 during maneuvering).Alternatively, the deployed flexible membrane 116 can be spaced awayfrom the payload base 114, although tensioning the flexible membrane 116against or otherwise in contact with the payload base 114 can increasethe deployed first mode frequency relative to that of a deployedflexible membrane 116 that is spaced away from the payload base 114.

In yet another implementation, one or more points of the interior regionof the flexible membrane 116 are anchored to or in contact with the bodyof the payload base 114 (as opposed to the extendable radial booms ofthe payload base 114) to provide inward or outward tension or planarstability. For example, in one implementation, the payload base 114includes a raised surface or structure to provide an outward tensioningagainst the middle of the flexible membrane 116 to pushing the flexiblemembrane 116 away from the payload base 114 (e.g., out-of-plane with theperiphery of the flexible membrane 116 in a deployed state). In anotherexample, the payload base 114 provides an anchor attached to the middleof the flexible membrane 116, so as to maintain a predeterminedseparation between the facing surface 120 and the flexible membrane 116or to pull the interior region of the flexible membrane 116 toward thefacing surface 120 (e.g., out-of-plane with the periphery of theflexible membrane 116 in a deployed state).

An (extendable) orthogonal boom 122 extends from the opposite surface124 of the payload base 114. The orthogonal boom 122 anchors lanyards,tapes, or other connectors that are attached to or near the distal endsof the radial booms 118 to provide additional structural support tothose radial booms 118 in the deployed state.

In the next (deployed) phase, the deployable system 102 is maneuvered sothat (1) one side of the flexible membrane 116 (which, in this example,supports photovoltaic devices) is directed to receive solar raysefficiently from the Sun 106, and (2) the opposing side of the flexiblemembrane 116 is directed for radiofrequency communications withterrestrial communications sites on the Earth 104. Typically, thedeployable system 102 remains in this orientation while in orbit,although the deployable system 102 may be maneuvered into otherorientations as needed. In this configuration, for example, thedeployable system 102 can provide a deployed flexible membrane thatgenerates power from a photovoltaic array and provides RF communicationsfrom an RF antenna, although other configurations and devices may beemployed.

FIGS. 2A-2C illustrate an example deployable system 200 in an undeployedstate. The deployable system 200 includes a flexible membrane 202capable of supporting a device or multiple devices so as to realize alarge aperture for the device or devices. Generally, the deployablesystem 200 includes a payload base 204 and the flexible membrane 202,wherein the payload base 204 includes a deployment system that unfurlsthe flexible membrane from an undeployed state to a deployed state. Inthe undeployed state illustrated in FIGS. 2A-2C, the payload base 204and the flexible membrane 202 are contained within a payload stage of alaunch vehicle, as indicated by the payload fairings 206. In someimplementations, a launch restraint cage (not shown) is positionedbetween the flexible membrane 202 and the payload fairings 206 (see,e.g., FIGS. 3A and 3B) and the descriptions thereof for details relatingto the launch restraint cage).

FIG. 2A illustrates a partial cross-sectional view from a side of theexample deployable system 200 in an undeployed state. The payloadfairings 206 are configured to fall away during deployment. When stowed,the flexible membrane 202 is rolled about a roll axis 208 to form acylindrical geometric shape and positioned atop a rotational platform210, which is located between the payload base 204 and the flexiblemembrane 202.

The deployment system of the payload base 204 includes multiple boomports 212 from which radial booms extend (e.g., in a telescoping format,in a carpenter's tape format, in a one-dimensional extendable boomformat) during deployment of the flexible membrane 202. Locations nearthe perimeter of an expanded form of the flexible membrane 202 areattached to ends of the radial booms (e.g., distal ends of the radialbooms relative to the payload base 204). (The attachment elements arenot shown in FIGS. 2A-2C.) In one implementation, the attachmentelements connect perimeter locations on the flexible membrane 202 (e.g.,perimeter with reference to the expanded format of the flexible membrane202) to or near distal ends of the radial booms (e.g., distal in thesense that the distal end of a radial boom extends away from the payloadbase 204 during deployment). Accordingly, as the radial booms extend,the ends of the radial booms push and/or pull to unroll and/or unfoldthe flexible membrane 202 from its undeployed state to its deployedstate.

Because the flexible membrane 202 includes one or more semi-rigidpanels, the flexible membrane 202 is rolled into the cylindricalgeometric shape under an expansive load. Accordingly, in at least oneimplementation, the rolled flexible membrane is contained within alaunch restraint cage (not shown), which is positioned between thepayload fairings 206 and the flexible membrane (see, e.g., FIG. 3 ), inthe undeployed state. During deployment, the launch restraint cage isreleased/opened, and the flexible membrane 202 partially unrolls inresponse to the expansive load, which is no longer constrained withinthe launch restraint cage.

FIG. 2B illustrates a partial cut-away perspective view of an exampledeployable system 200 in an undeployed state. The payload fairings 206fall away during deployment. The flexible membrane 202 is rolled about aroll axis (which has a position indicated by the dashed line “x” in thecenter of the roll) to form a cylindrical geometric shape and positionedatop a rotational platform 210, which is positioned between the payloadbase 204 and the flexible membrane 202. The rolling direction (duringstowage) and the unrolling direction (during deployment) are shown bythe dashed line arrow 220, although the directions for rolling/unrollingare interchangeable depending upon design constraints.

The deployment system of the payload base 204 includes multiple boomports 212 from which radial booms extend (e.g., in a one-dimensionalformat) during deployment of the flexible membrane 202. Locations nearthe perimeter of an expanded form of the flexible membrane 202 areattached to or near distal ends of the radial booms (e.g., distal endsof the radial booms relative to the payload base 204). (The attachmentelements are not shown in FIGS. 2A-2C.) Accordingly, as the radial boomsextend radially from the roll axis of the payload base 204, the distalends of the radial booms push and/or pull to unroll and/or unfold theflexible membrane 202 from its undeployed state to its deployed state.

FIG. 2C illustrates a partial cut-away perspective view of an exampledeployable system in an undeployed state, revealing the rotationalplatform 210 between the flexible membrane 202 and the payload base 204.The payload fairings 206 fall away during deployment. The flexiblemembrane 202 is rolled about a roll axis (which has a position indicatedby the dashed line “x” in the center of the roll) to form a cylindricalgeometric shape and positioned atop a rotational platform 210, which ispositioned between the payload base 204 and the flexible membrane 202.The rolling direction (during stowage) and the unrolling direction(during deployment) are shown by the dashed line arrow 220, although thedirections for rolling/unrolling are interchangeable depending upondesign constraints.

The deployment system of the payload base 204 includes multiple boomports 212 from which radial booms extend (e.g., in a one-dimensionalextendable boom format, in a telescoping format, in a carpenter's tapeformat) during deployment of the flexible membrane 202. Locations nearthe perimeter of an expanded form of the flexible membrane 202 areattached to or near the distal ends of the radial booms (e.g., distalends of the radial booms relative to the payload base 204). (Theattachment elements are not shown in FIGS. 2A-2C but may includelanyards, tapes, and other types of attachment features) Accordingly, asthe radial booms extend radially from the roll axis of the payload base204, the distal ends of the radial booms push and/or pull to unrolland/or unfold the flexible membrane 202 from its undeployed state to itsdeployed state.

The flexible membrane 202 is positioned on the rotational platform 210(e.g., pulled into contact with the rotational platform 210 by a launchretention cage and/or the taut attachments to the distal ends of theradial booms). When the flexible membrane 202 is stowed into anundeployed state, one or more small-radius loops are formed from one ormore middle or near-middle portions of the flexible membrane 202, asdescribed with regard to subsequent figures, and the rest of theflexible membrane 202 is rolled about these loops. As such, the one ormore small-radius loops are positioned within the interior of thecylindrical geometric shape formed by the rolled flexible membrane, witheach small-radius loop having a smaller radius than the interior of thecylindrical geometric shape.

In one implementation, two synchronization pins 222 are positioned onthe rotational platform 210, although more or less than twosynchronization pins may be employed. In an implementation including aflexible membrane 202 having two small-radius loops, the flexiblemembrane 202 is installed on the rotational platform 210 such that eachsynchronization pin is inserted into one of the small-radius loops toreleasably anchor the small-radius loops to the rotational platform 210.Rotation of the rotational platform 210 is synchronized with theextension rate of the radial booms so that the flexible membrane 202unrolls about a roll axis and unfolds along a z-fold axis at controlledrates as the radial booms expand.

In one implementation, the synchronization coordinates the rate at whichthe rotational platform 210 allows the flexible membrane 202 to unrollabout the roll axis with the rate at which the flexible membrane 202unfolds along the z-fold axis, with both unrolling and unfoldingresulting from the outward extension of the radial booms. In oneexample, the rotational platform 210 allows rotation (and thereforeunrolling) primarily during an initial phase of deployment, with thatrotation tracking with the rate at which the radial booms are extendingthe distal ends of the rolled flexible membrane. In this initial phase,the flexible membrane 202 is concurrently unrolling and unfolding. Atthe end of the initial phase, the flexible membrane 202 is fullyunrolled, and the remaining deployment phase is primarily the continuedunfolding of the flexible membrane 202 as the radial booms continue toextend. In one implementation, the synchronization pins 222 are releasedfrom the small-radius loops (as they disappear when unrolling iscompleted) and are able to fold down (e.g., on hinges) against therotational platform 210, out of the way.

FIGS. 3A-3D illustrate an example flexible membrane 300 with respect toa launch restraint cage 302. In one implementation, the launch restraintcage 302 is positioned between the payload fairings (see FIG. 2 ) andthe flexible membrane 300. It should be understood that other launchrestraints may be employed to constrain the flexible membrane 300 untilthe start of a deployment.

FIG. 3A illustrates a side view of the flexible membrane 300 in anundeployed state contained within the launch restraint cage 302, whichis closed. The flexible membrane 300 is positioned on a payload base 304from which extendable radial booms can be extended from radial boomports 306. Restraint arms 308 of the launch restraint cage 302 are shownas closed around the flexible membrane 300. In one implementation, thelaunch restraint cage 302 constrains the expansive load of the flexiblemembrane 300 in the rolled format.

FIG. 3B illustrates a perspective view of the flexible membrane 300 inan undeployed state contained within the launch restraint cage 302,which is closed. The flexible membrane 300 is positioned on a payloadbase 304 from which extendable radial booms can be extended from radialboom ports 306. Restraint arms of the launch restraint cage 302 areshown as closed around the flexible membrane 300. In one implementation,the launch restraint cage 302 constrains the expansive load of theflexible membrane 300 in the rolled format.

FIG. 3C illustrates a side view of the flexible membrane 300 in anundeployed state released from the launch restraint cage 302, which hasbeen opened (by the expansive load of the flexible membrane 300 and/orby other motive forces such as additional springs or gears). In someimplementation, the opening of the restraint arms of the launchrestraint cage 302 is dampened to control the rate at which therestraint arms release. Such dampening can also release the expansiveload of the rolled flexible membrane more slowly than without dampening.

The flexible membrane 300 is positioned on a payload base 304 from whichextendable radial booms can be extended from radial boom ports 306.Restraint arms of the launch restraint cage 302 are shown as open fromthe flexible membrane 300, and the radial booms can extend between thespaces between the open restraint arms of the launch restraint cage 302.In one implementation, the launch restraint cage 302 no longerconstrains the expansive load of the flexible membrane 300 in the rolledformat. As such, while not shown in FIG. 3C, the flexible membrane 300can begin to unroll, at least in part, as a result of this releasedexpansive load (see, e.g., the partially unrolled flexible membrane 700of FIG. 7A).

FIG. 3D illustrates a perspective view of the flexible membrane 300 inan undeployed state released from the launch restraint cage 302, whichhas been opened. The flexible membrane 300 is positioned on a payloadbase 304 from which extendable radial booms can be extended from radialboom ports 306. Restraint arms of the launch restraint cage 302 areshown as open from the flexible membrane 300, and the radial booms canextend between the spaces between the open restraint arms of the launchrestraint cage 302. In one implementation, the launch restraint cage 302no longer constrains the expansive load of the flexible membrane 300 inthe rolled format. As such, while not shown in FIG. 3C, the flexiblemembrane 300 can begin to unroll (as shown by the dashed arrow 312), atleast in part, as a result of this released expansive load (see, e.g.,the partially unrolled flexible membrane 700 of FIG. 7A).

It should be understood that, while the flexible membrane 300 may beginto unroll about a roll axis (as suggested by the arrow 312) after thelaunch restraint cage 302 is opened (due to the released expansiveload), in an alternative implementation, a rotation platform upon whichthe flexible membrane 300 is mounted can initially dampen, limit, ordelay rotation after the launch restraint cage 302 is opened.Nevertheless, the ends of the folded and rolled flexible membrane 300(e.g., on the outer circumference of the cylindrical geometric shape ofthe rolled flexible membrane 300) may begin to unroll or expand from theconstrained shape, with or without rotation of the flexible membrane 300on the rotation platform, as a result of the released expansive load.

The illustrated implementation shows six restraint arms 308 that hingebetween a closed cage state and an open cage state. In otherimplementations, the launch restraint cage 302 may include a larger orsmaller number of restraint arms. Furthermore, the six restraint arms308 are shown as hinging from hinge locations 310 on the payload base304 between the radial boom ports 306 and the flexible membrane 300. Inother implementations, one or more of the restraint arms may hinge fromlocations on the other side of the payload base 304 (e.g., such that theradial boom powers 306 are positioned between the flexible membrane 300and the hinge locations 310) or some other location.

FIGS. 4A and 4B illustrate an example flexible membrane 400 of adeployable system 402 in a deployed state. The flexible membrane 400includes a thin periphery region at the perimeter of the flexiblemembrane 400. The thin periphery region encloses an interior regioncomprising the majority of the flexible membrane area. The flexiblemembrane 400 is tensioned by extended radial booms 408 so as to form asurface with a first side 404 and a second side 406. In oneimplementation, the first side 404 of the flexible membrane 400 includessemi-rigid panels that support photovoltaic devices and the second side406 of the flexible membrane 400 includes semi-rigid panels that supportradiofrequency devices (e.g., of an RF antenna), although other devices(or no devices) may be employed on either side of the flexible membrane400.

Notably, the deployed flexible membrane 400 is a continuous structurewithin the closed periphery formed by the outer perimeter of theflexible membrane 400 in both the deployed state and the undeployedstate. For example, no radial or orthogonal boom or any portion of thepayload base 410 penetrates the interior of the flexible membrane 400.Furthermore, the flexible membrane 400 is not deployed in multiplepieces or with disconnections between panels that are subsequentlyconnected together.

Both the payload base 410 and the radial and orthogonal booms arelocated on one side of the continuous structure of the deployed flexiblemembrane 400. No portion of the payload base 410 is located adjacent tothe second side 406 of the deployed flexible membrane 400. As such, thefirst side 404 of the deployed flexible membrane 400 is located betweenthe second side 406 of the deployed flexible membrane 400 and thepayload base 410. This configuration provides an external view of thesecond side 406 of the deployed flexible membrane as not portion of thesecond side 406 is obscured by the radial and orthogonal booms, thepayload base, and the launch restraint cage.

The deployment structure of the payload base 410 includes six extendableradial booms 408 that, when extended, form a six-pointed star. The stardefines a plane that is substantially parallel to the surface of thedeployed flexible membrane, although the surface of the deployedflexible membrane may be planar, curved, undulating, or in the form of asimilar surface. The deployment structure of the payload base 410 alsoincludes an orthogonal boom, e.g., an out-of-plane boom (not shown)that, when extended, is substantially orthogonal to the plane defined bythe extendable radial booms 408. One or more lanyards (not shown) extendfrom the end of the orthogonal boom to the distal end of each of theradial booms 408. The orthogonal boom and lanyards operate to supportthe tension on the radial booms 408 of the six-pointed star and,therefore, on the surface of the deployed flexible membrane 400. Itshould be understood that a larger or smaller number of booms may beemployed in different implementations.

In the illustrated embodiment, each of the extendable booms may employcarpenter's tapes, battens, and diagonals, when deployed, to create anextendable boom. Other types of booms can be employed. For example,booms that employ flexible rods or telescoping rods or members can beemployed. Further, the type of boom that can be employed may depend onthe length over which the boom is designed to extend in the deployedstate. For example, if the boom only needs to extend a relatively shortdistance, a boom realized with a single carpenter's tape may befeasible. Alternatively, one-dimensional extendable booms or telescopingrods or members may be beneficial to support larger area membranes.Further, in certain applications, an orthogonal boom may be unnecessary.Further, two or more different types of extendable booms can be employedif needed or desired.

FIGS. 5A and 5B illustrate a payload base 500 of an example deployablesystem. The payload base 500 include a spacecraft bus or a satellitebus. As such, the payload base 500 may contain without limitation avariety of different sub-systems, such as any combination of navigationsub-systems, propulsion sub-systems, control sub-systems, communicationsub-systems, power sub-systems, membrane-deploying sub-systems, and anyother payload sub-systems used in a spacecraft or satellite bus.

FIG. 5A illustrates a first side 502 of the payload base 500, whichfaces away from the flexible membrane in both the undeployed state andthe deployed state. Multiple radial boom ports 504 are provided toextend radial booms (not shown) from the payload base 500 duringdeployment. An orthogonal boom port 506 is positioned on the first side502 of the payload base 500. An orthogonal boom (not shown) extends fromthe orthogonal boom port 506 during deployment, after which one or morelanyards (not shown) connect the distal end of the extended orthogonalboom to the distal ends of the radial booms.

FIG. 5B illustrates a second side 508 of the payload base 500, whichfaces the flexible membrane in both the undeployed state and thedeployed state. Multiple radial boom ports 504 are provided to extendradial booms (not shown) from the payload base 500 during deployment. Arotational platform 510 is positioned on the second side 508 and canrotate about the roll axis. The rotational platform 510 is designed tobe positioned between the payload base 500 and the flexible membrane inboth the undeployed state and the deployed state.

One or more synchronization pins 512 are mounted on the rotationalplatform to releasably-anchor the rolled flexible membrane in theundeployed state and during at least part of the deployment. The rolledflexible membrane can be releasably anchored to the synchronization pins512 in a variety of ways, such as by inserting a synchronization pin ina small-diameter loop of the flexible membrane in the interior of thecylindrical geometric shape, employing a sleeve into which asynchronization pin is inserted until some point in the deployment (atwhich point it releases) or some other manner. Rotation of therotational platform 510 is synchronized with the extension of the radialbooms to control the relative rates of unrolling and unfolding duringdeployment. In one implementation, the synchronization pins 512 folddown or retract at some point in the deployment so as not to interferewith the surface of the deployed flexible membrane.

While the description and drawings suggest the same number ofsynchronization pins as small-radius loops, it should be understood thatthe number of synchronization pins and small-radius loops in otherimplementations may vary and may include a different number of pins thanloops. For example, a system may include two small-radius loops but onlyone synchronization pin.

FIG. 6 illustrates an example deployable system 600 in a deployed state,including a payload base 602 attached to a flexible membrane 604. Inthis deployed state, radial booms 606 have extended from the payloadbase 602, unrolling and unfolding the flexible membrane from its stowedformat (e.g., a cylindrical geometric shape) to its expanded formathaving a larger area than the stowed format (e.g., to provide a planarsurface, a roughly planar surface, a curved surface, or some othercontoured surface. In one implementation, the flexible membrane 604 isto one side of the payload base 602 (out of plane), while the payloadbase 602 and the distal ends of the radial booms (when extended) aresubstantially in the same plane. As such, in the deployed state, theflexible membrane 604 is tensioned against or otherwise in contact withone face or surface of the payload base 602 to form a curved orcontoured surface (as shown in FIG. 1 ) in the flexible membrane 604. Inanother implementation, the surface is flat or planar and may or may notbe secured to the payload bus at the center of the payload base 602 orits rotational platform, synchronization pins, etc.

An orthogonal boom 608 is also shown to have extended from the payloadbase 602 (e.g., parallel to the roll axis and orthogonal to the z-foldaxis and the plane of the distal ends of the radial booms) in thedeployed state. One or more lanyards, tapes, or other connectors areattached between the distal end of the orthogonal boom 608 and thedistal ends of the radial booms 606, to provide additional structuralsupport in the deployed state.

FIGS. 7A-7D illustrate four phases of deployment of a flexible membraneof an example deployable system in a perspective view from a first side.The first side faces away from the payload base and booms, whichtherefore do not obscure any area of the first side after deployment. Assuch, this unobscured first side of the flexible membrane 700 issuitable for radiofrequency devices, although other devices may beemployed.

FIG. 7A illustrates an early phase of deployment that includes anunrolling aspect in which the flexible membrane 700 rotates about a rollaxis 701 on a rotational platform on the payload base (not shown). Nounfolding along a z-fold axis 703 is shown in FIG. 7A, although bothunrolling and unfolding can happen concurrently at the early phase(s) ofdeployment in some implementations.

FIG. 7B illustrates a subsequent phase of deployment in which most ofthe unrolling has been completed, and deployment of the flexiblemembrane 700 is transitioning into a primarily or exclusively unfoldingphase along the z-fold axis 703. FIG. 7C illustrates yet anothersubsequent phase of deployment of the flexible membrane 700 in which allof the unrolling has been completed, and deployment is transitioninginto exclusively unfolding phase along the z-fold axis 703. FIG. 7Dillustrates yet another subsequent phase of deployment in which theflexible membrane 700 has been fully unrolled and unfolded. The radialbooms extend farther from the payload base with each successive phase.Accordingly, in the deployed state, the roll axis is substantiallyorthogonal to the flexible membrane surface, which lies along the z-foldaxis.

FIGS. 8A-8C illustrate three phases of deployment of a flexible membrane800 of an example deployable system in a perspective view from a secondside. The second side faces the payload base 802 and radial booms 804,which, therefore, can obscure one or more areas of the second side afterdeployment. As such, this obscured second side of the flexible membrane800 is suitable for photovoltaic devices, although other devices may beemployed.

An early phase (not shown) of deployment of the flexible membrane 800includes an unrolling aspect in which the flexible membrane 800 rotatesabout a roll axis on a rotational platform on the payload base 802without any unfolding along a z-fold axis, although both unrolling andunfolding can happen concurrently at the early phase(s) of deployment insome implementations.

FIG. 8A illustrates a subsequent phase of deployment in which most ofthe unrolling has been completed, and deployment of the flexiblemembrane 800 is transitioning into a primarily or exclusively unfoldingphase along the z-fold axis. FIG. 8B illustrates yet another subsequentphase of deployment of the flexible membrane 800 in which all of theunrolling has been completed, and deployment is transitioning intoexclusively unfolding phase along the z-fold axis. FIG. 8C illustratesyet another subsequent phase of deployment of the flexible membrane 800in which the flexible membrane has been fully unrolled and unfolded. Theradial booms 804 extend farther from the payload base 802 with eachsuccessive phase.

FIG. 9 illustrates z-fold lines (see, e.g., z-fold 900) in an exampleflexible membrane 902 having a semi-rigid support member 904 at one endof the example flexible membrane 902. The semi-rigid cylinder supportmember 904 is more rigid than the semi-rigid panels in the flexiblemembrane 902 (particularly sufficiently rigid along the roll axis toreduce or eliminate compression and/or collapsing of the cylindricalgeometric shape), although it is still flexible enough to be rolledabout the roll axis and/or into the small-radius loop. Numerous z-foldsare shown in sequence along a z-fold axis 906. During some phases ofdeployment, the flexible membrane 902 is unfolded along the z-fold axis906 as radial booms expand to their fully extended positions.

In one implementation, the flexible membrane 902 includes a thinflexible substrate fabric on which are mounted multiple panels (notshown) for supporting zero or more devices or portions of devices.Individual panels are attached to the thin flexible substrate fabricbetween each z-fold (such as in regions 920 and 922) so that the z-foldsare between two or more adjacent panels. The thin flexible substratefabric may be further perforated at the z-folds to facilitate controlledfolding and unfolding. Furthermore, such perforations address a shearingissue between the panels adjacent panels separated by a z-fold. Such ashearing issue arises when the flexible membrane 902 is rolled afterbeing first Z-folded.

In another implementation, the flexible membrane 902 includes multiplepanels (not shown) without being mounted on a thin flexible substratefabric. Instead, the two semi-rigid panels are positioned adjacent toeach other (such as at regions 920 and 922) and connected to each otherby one or more shear compliant connectors, such that the z-folds arepositioned at the junction between the two adjacent panels.

The flexible membrane 902 also includes the semi-rigid support member904 that serves to prevent the flexible membrane 902, when in theundeployed state, from collapsing inward in the cylindrical geometricshape. Such a collapse could prevent subsequent deployment of theflexible membrane 902.

With reference to the blow-out view 908 of FIG. 9 , the semi-rigidsupport member 904 includes a hook structure 910 and a beveled end 912that captures the hook structure 910 when the flexible membrane 902 isrolled to prevent the ends of a relatively rigid interior wallestablished with the semi-rigid support member 904 from slipping pastone another.

FIG. 10 illustrates partially folded z-folds (such as z-fold 1000) in anexample flexible membrane 1002 having a semi-rigid support member 1004at one end of the example flexible membrane 1002. Unfolding along az-fold axis of the flexible membrane 1002 is an early step intransitioning the flexible membrane 1002 from the undeployed state showninto a deployed state.

FIG. 11A illustrates a top view and FIG. 11B illustrates a perspectiveview of an example flexible membrane 1100 rolled about a roll axis intoa cylindrical geometric shape of an undeployed state and having asmall-radius loop 1102 positioned within the interior 1104 of thecylindrical geometric shape. After the flexible membrane 1100 has beenz-folded into layers of stacked panels, the flexible membrane 1100 isrolled beginning near the middle of the flexible membrane 1100 (e.g., ofthe stacked panels) resulting from the z-folding so that a semi-rigidsupport member 1106 (see, e.g., semi-rigid support member 904 of FIG. 9) can form an inner wall of the undeployed flexible membrane 1100 withinthe interior of the cylindrical geometric shape. The beveled end 1110 ofthe semi-rigid support member 1106 is captured by the hook structure1108 of the semi-rigid support member 1106 to prevent the ends of therigid wall from slipping past one another. Notably, by rolling from themiddle of the stack of panels associated with the z-folded membrane, thesmall radius loop 1102 is formed in the undeployed flexible membrane1100 in the interior of the cylindrical geometric shape. Also, in theillustrated implementations, the wall of the interior of the cylindricalgeometric shape is established using the semi-rigid support member 1106and forms a relatively large “comma” or “paisley-like” shape in relationto the small radius loop 1102, which forms a loop space 1112 with arelatively small “comma” or “paisley-like” shape.

FIG. 12 illustrates a rolling and unrolling of an example flexiblemembrane 1200 about a roll axis (indicated by the dashed line “x” at thecenter of the roll) between an undeployed state and a (partially)deployed state, wherein the flexible membrane 1200 forms a cylindricalgeometric shape with a small-radius loop positioned within the interiorof the cylindrical geometric shape. In one implementation, thesmall-radius loops 1202 is formed as an initial bend or roll at or nearthe middle of the z-folded flexible membrane. After the initial bend orroll (which results in the small-radius loop 1202), the remaining lengthof the z-folded flexible membrane is rolled around the small-radius loop1202 to form the cylindrical geometric shape that exists in theundeployed state. A semi-rigid support member 1204 forms at least aportion of the interior wall of the cylindrical geometric shape toprovide structural support to the flexible membrane 1200. Duringdeployment, the rolled and z-folded flexible membrane is unrolled aboutthe roll axis and unfolded to reach the deployed state.

FIG. 13 illustrates z-fold lines (see, e.g., z-fold 1300) in an exampleflexible membrane 1302 having semi-rigid support members 1304 atopposite ends of the example flexible membrane. Numerous z-folds areshown in sequence along a z-fold axis 1306. During some phases ofdeployment, the flexible membrane 1302 is unfolded along the z-fold axis1306 as radial booms expand to their fully extended positions.

In one implementation, the flexible membrane 1302 includes a thinflexible substrate fabric on which are mounted multiple panels (notshown) for supporting zero or more devices or portions of devices.Individual panels are attached to the thin flexible substrate fabricbetween each z-fold so that the z-folds are between two or more adjacentpanels. The thin flexible substrate fabric may be further perforated atthe z-folds to facilitate controlled folding and unfolding. Furthermore,such perforations address a shearing issue between the panels adjacentpanels separated by a z-fold. Such a shearing issue arises when theflexible membrane 1302 is rolled after being first z-folded.

In another implementation, the flexible membrane 1302 includes multiplepanels (not shown) without being mounted on a thin flexible substratefabric. Instead, the two semi-rigid panels are positioned adjacent toeach other and connected to each other by one or more shear compliantconnectors, such that the z-folds are positioned at the junction betweenthe two adjacent panels.

The flexible membrane 1302 also includes multiple semi-rigid supportmembers 1304 that serve to prevent the flexible membrane 1302, when inthe undeployed state, from collapsing inward in the cylindricalgeometric shape. Such a collapse could prevent subsequent deployment ofthe flexible membrane 1302. In the illustrated implementation, thesemi-rigid support members 1304 are positioned near the middle ofopposite ends of the flexible membrane 1302 along the z-fold axis. 1306.

As discussed with reference to the blow-out view 908 of FIG. 9 , thesemi-rigid support members 1304 each include a hook structure and abeveled end that captures the hook structure when the flexible membraneis rolled to prevent the ends of a relatively rigid interior wallestablished with the semi-rigid support member 1304 from slipping pastone another.

FIGS. 14A-14B illustrate an example flexible membrane rolled about aroll axis into a cylindrical geometric shape of an undeployed state andhaving two small-radius loops positioned within the interior of thecylindrical geometric shape. FIG. 14A illustrates a top view and FIG.14B illustrates a perspective view of an example flexible membrane 1400rolled about a roll axis into a cylindrical geometric shape of anundeployed state and having a first small-radius loop 1402 and a secondsmall-radius loop 1403 positioned within the interior of the cylindricalgeometric shape.

After the flexible membrane 1400 has been z-folded into layers ofstacked panels, the flexible membrane 1400 is rolled beginning near themiddle of the flexible membrane 1400 (e.g., of the stacked panels)resulting from the z-folding so that a semi-rigid support members 1406(see, e.g., semi-rigid support member 1304 of FIG. 13 ) can form innerwalls of the undeployed flexible membrane 1400 within the interior ofthe cylindrical geometric shape. The beveled ends 1410 of eachsemi-rigid support member 1406 is captured by the hook structure 1408 ofthe semi-rigid support member 1406 to prevent the ends of the rigid wallfrom slipping past one another. Notably, by rolling from the middle ofthe stack of panels associated with the z-folded membrane, the smallradius loop 1402 and 1403 are formed in the undeployed flexible membrane1400 in the interior of the cylindrical geometric shape. Also, in theillustrated implementations, the wall of the interior of the cylindricalgeometric shape is established using the semi-rigid support members 1406and form two loop spaces 1412 and 1413 with relatively small “comma” or“paisley-like” shapes (as compared to the radius of the interior of thecylindrical geometric shape).

FIG. 15 illustrates a rolling and unrolling of an example flexiblemembrane 1500 about a roll axis (indicated by the dashed line “x” at thecenter of the roll) between an undeployed state and a (partially)deployed state, wherein the flexible membrane 1500 forms a cylindricalgeometric shape with two small-radius loops 1502 and 1504 positionedwithin the interior of the cylindrical geometric shape. In oneimplementation, the small-radius loops 1502 and 1504 are formed asinitial bends at or near the middle of the z-folded flexible membrane.After the initial bends (which result in the small-radius loops 1502 and1504), the remaining length of the z-folded flexible membrane is rolledaround the small-radius loops 1502 and 1504 to form the cylindricalgeometric shape that exists in the undeployed state. Two semi-rigidsupport members 1506 and 1508 form at least a portion of the interiorwall of the cylindrical geometric shape to provide structural support tothe flexible membrane 1500. During deployment, the rolled and z-foldedflexible membrane is unrolled about the roll axis and unfolded to reachthe deployed state.

FIG. 16 illustrates a phase of z-folding operation on an exampleflexible membrane 1600. The flexible membrane 1600 includes a thincontinuous flexible substrate fabric 1602 and one or more semi-rigidpanels (see, e.g., panels 1604, 1606, and 1608) mounted to at least oneside surface of the thin continuous flexible substrate fabric 1602. (InFIG. 16 , the panels are only shown as mounted on one side surface ofthe thin continuous flexible substrate fabric 1602, although, in otherimplementations, panels may also be mounted on the opposite side surfaceof the thin continuous flexible substrate fabric 1602.) Each semi-rigidpanel can support zero or more devices or portions of devices.

A z-fold location 1610 is shown at the junction between adjacent panels1604 and 1606. The panel 1604 can be folded at the z-fold location 1610relative to the panel 1606 as the flexible membrane 1600 is beingtransitioned to an undeployed state and can be unfolded at the z-foldlocation 1610 as the flexible membrane 1600 is being expanded to adeployed state. A junction is shown between the panels 1606 and 1608,although the flexible membrane 1600 is not shown as folded in FIG. 16 atthe corresponding z-fold location 1612.

FIG. 17 illustrates another phase of z-folding operation on an exampleflexible membrane 1700. The flexible membrane 1700 includes a thincontinuous flexible substrate fabric 1702 and one or more semi-rigidpanels (see, e.g., panels 1704, 1706, and 1708) mounted to at least oneside surface of the thin continuous flexible substrate fabric 1702. (InFIG. 17 , the panels are only shown as mounted on one side surface ofthe thin continuous flexible substrate fabric 1702, although, in otherimplementations, panels may also be mounted on the opposite side surfaceof the thin continuous flexible substrate fabric 1702.) Each semi-rigidpanel can support zero or more devices or portions of devices.

A z-fold location 1710 is shown at the junction between adjacent panels1704 and 1706. The panel 1704 has been folded at the z-fold location1710 relative to the panel 1706 as the flexible membrane 1700 is beingtransitioned to an undeployed state and can be unfolded at the z-fold1710 as the flexible membrane 1700 is being expanded to a deployedstate. Furthermore, another z-fold location 1712 is shown at thejunction between adjacent panels 1706 and 1708. The panel 1708 can befolded at the z-fold location 1712 relative to the panel 1706 as theflexible membrane 1700 is being transitioned to an undeployed state andcan be unfolded at the z-fold locations 1710 and 1712 as the flexiblemembrane 1700 is being expanded to a deployed state.

FIG. 18 illustrates yet another phase of z-folding operation on anexample flexible membrane. The flexible membrane 1800 includes a thincontinuous flexible substrate fabric 1802 and one or more semi-rigidpanels (see, e.g., panels 1804, 1806, and 1808) mounted to at least oneside surface of the thin continuous flexible substrate fabric 1802. (InFIG. 18 , the panels are only shown as mounted on one side surface ofthe thin continuous flexible substrate fabric 1802, although, in otherimplementations, panels may also be mounted on the opposite side surfaceof the thin continuous flexible substrate fabric 1802.) Each semi-rigidpanel can support zero or more devices or portions of devices.

A z-fold location 1810 is shown at the junction between adjacent panels1804 and 1806. The panel 1804 has been folded at the z-fold location1810 relative to the panel 1806 as the flexible membrane 1800 is beingtransitioned to an undeployed state and can be unfolded at the z-fold1810 as the flexible membrane 1800 is being expanded to a deployedstate. Furthermore, another z-fold location 1812 is shown at thejunction between adjacent panels 1806 and 1808. The panel 1808 can befolded at the z-fold location 1812 relative to the panel 1806 as theflexible membrane 1800 is being transitioned to an undeployed state andunfolded at the z-fold locations 1810 and 1812 as the flexible membrane1800 is being expanded to a deployed state.

The thin continuous flexible substrate fabric 1802 (e.g., withperforations along the z-fold locations) provides a shear compliantconnection at the junction between adjacent panels. In the undeployedstate, the flexible membrane 1800 forms a stack of connected panelsmounted on the thin continuous flexible substrate fabric 1802. In adeployed state, the flexible membrane 1800 forms an expanded andcontinuous membrane of connected panels mounted on the thin continuousflexible substrate fabric 1802.

FIG. 19 illustrates a phase of z-folding operation on an exampleflexible membrane 1900. The flexible membrane 1900 includes semi-rigidpanels (see, e.g., panels 1904, 1906, and 1908) connected by one or moreshear compliant connectors (see, e.g., connectors 1920 and 1922). In oneimplementation, the shear compliant connectors are configured as loopconnectors that slide through apertures (e.g., apertures 1924, 1926,1928, and 1930) along the edge and in the interior of each panel,although other shear compliant connectors implementations may beemployed. Such connectors may be looped through interior regionapertures in the panels, pivotably anchored to the surfaces of thepanels in the interior region of the panels, or otherwise pivotablyfastened to the interior region of the panels. In anotherimplementation, such connectors are fixed (e.g., not pivotably anchored)in their attachment to the interior region of the panels and have enoughflexibility to accommodate shear motion. In some implementations, theconnectors all connect to the same side of the flexible membrane 1900.In other implementations, the connectors connector on both sides of theflexible membrane 1900 and/or weave throughout multiple panels on bothsides of the flexible membrane 1900.

Each panel can support devices on one or both sides of the panels. Inanother implementation, each panel includes at least two panel layers,with devices supported on one side of each panel layer. Each semi-rigidpanel or panel layer can support zero or more devices or portions ofdevices.

A z-fold location 1910 is shown at the junction between adjacent panels1904 and 1906. The panel 1904 can be folded at the z-fold location 1910relative to the panel 1906 as the flexible membrane 1900 is beingtransitioned to an undeployed state and can be unfolded at the z-foldlocation 1910 as the flexible membrane 1900 is being expanded to adeployed state. A junction is shown between the panels 1906 and 1908,although flexible membrane 1900 is not shown as folded in FIG. 19 at thecorresponding z-fold location 1912.

FIG. 20 illustrates another phase of z-folding operation on an exampleflexible membrane 2000. The flexible membrane 2000 includes semi-rigidpanels (see, e.g., panels 2004, 2006, and 2008) connected by one or moreshear compliant connectors (see, e.g., connectors 2020 and 2022). In oneimplementation, the shear compliant connectors may be in a string formatconnected to apertures (e.g., apertures 2024, 2026, 2028, and 2030) inthe interior of each panel. In another implementation, the shearcompliant connectors are configured as loop connectors that slidethrough apertures (e.g., apertures 2024, 2026, 2028, and 2030) along theedge and in the interior of each panel, although other shear compliantconnectors implementations may be employed. Each semi-rigid panel cansupport zero or more devices or portions of devices.

A z-fold location 2010 is shown at the junction between adjacent panels2004 and 2006. The panel 2004 has been folded at the z-fold location2010 relative to the panel 2006 as the flexible membrane 2000 is beingtransitioned to an undeployed state and can be unfolded at the z-fold2010 as the flexible membrane 2000 is being expanded to a deployedstate. Furthermore, another z-fold location 2012 is shown at thejunction between adjacent panels 2006 and 2008. The panel 2008 can befolded at the z-fold location 2012 relative to the panel 2006 as theflexible membrane 2000 is being transitioned to an undeployed state andcan be unfolded at the z-fold locations 2010 and 2012 as the flexiblemembrane 2000 is being expanded to a deployed state.

FIG. 21 illustrates yet another phase of z-folding operation on anexample flexible membrane. The flexible membrane 2100 includessemi-rigid panels (see, e.g., panels 2104, 2106, and 2108) connected byone or more shear compliant connectors (see, e.g., connectors 2120 and2122). In one implementation, the shear compliant connectors areconfigured as loop connectors that slide through apertures (e.g.,apertures 2124, 2126, 2128, and 2130) along the edge and in the interiorof each panel, although other shear compliant connectors implementationsmay be employed. Each semi-rigid panel can support zero or more devicesor portions of devices.

A z-fold location 2110 is shown at the junction between adjacent panels2104 and 2106. The panel 2104 has been folded at the z-fold location2110 relative to the panel 2106 as the flexible membrane 2100 is beingtransitioned to an undeployed state and can be unfolded at the z-fold2110 as the flexible membrane 2100 is being expanded to a deployedstate. Furthermore, another z-fold location 2112 is shown at thejunction between adjacent panels 2106 and 2108. The panel 2108 can befolded at the z-fold location 2112 relative to the panel 2106 as theflexible membrane 2100 is being transitioned to an undeployed state andunfolded at the z-fold locations 2110 and 2112 as the flexible membrane2100 is being expanded to a deployed state.

In the undeployed state, the flexible membrane 2100 forms a stack ofconnected panels mounted on the thin continuous flexible substratefabric 2102. In a deployed state, the flexible membrane 2100 forms anexpanded and continuous membrane of connected panels mounted on the thincontinuous flexible substrate fabric 2102.

FIGS. 22A-22D illustrate panels of an example flexible membrane 2200having shear compliant connectors 2202. With reference to FIGS. 22A and22B, the flexible membrane 2200 has a first panel 2204 and a secondpanel 2206 that are separated from one another across a junction but areconnected to one another by a series of flexible string elements or loopelements referred to as shear compliant connectors (see, e.g.,connectors 2208 and 2210). Each of the shear compliant connectors hasone end pivotally connected to the first panel 2204 via a hole oraperture extending through the first panel 2204 and another endpivotally connected to the second panel 2206 via a hole or apertureextending through the second panel 2206. The pivot connections are suchthat the each of the shear compliant connectors can pivot about an axisthat extends through each of the holes or apertures in the panels withwhich each such shear compliant connector is associated andperpendicular to the plane of the undeployed panel. The flexible natureof the series of shear compliant connectors allows the connectors to actas a folding restraint that allows the first and second panels 2204 and2206 to be Z-folded while accommodating shear that can be introducedwhen the flexible membrane 2200 is rolled. With reference to FIGS. 22Cand 22D, the series of shear compliant connectors, due to the ability topivot, reduces the shearing issue (see the offset positions of thepanels 2204 and 2206 in FIGS. 22C and 22D) that arises upon the rollingof the flexible membrane 2200 to place the flexible membrane 2200 in anundeployed state. In another implementation, such connectors are fixed(e.g., not pivotably anchored) in their attachment to the interiorregion of the panels and have enough flexibility to accommodate shearmotion.

As such, the string-like structures between two panels establish a hingewith a least two-degrees of rotational freedom, unlike a conventionalhinge with only a single rotational degree of freedom.

FIG. 23 illustrates example deployment operations 2300 for an exampledeployable system. A providing operation 2302 provides a flexiblemembrane that supports zero or more devices on at least one surface ofthe flexible membrane in an undeployed state. A releasing operation 2304releases the flexible membrane from a launch restraint cage duringdeployment.

An extending operation 2306 begins to extend radial booms from a payloadbase that is coupled to the flexible membrane. An unrolling operation2308 unrolls the flexible membrane about a roll axis to form a flexiblemembrane surface in a deployed state as the radial booms extend. Theroll axis is substantially perpendicular to the flexible membranesurface in the deployed state. An unfolding operation 2310 unfolds theflexible membrane along a z-fold axis into the deployed state as theradial booms extend. The extending operation 2306, the unrollingoperation 2308, and the unfolding operation 2310 can be performed in anyorder, concurrently, or partially concurrently (e.g., the unrollingoperation 2308 may cease while the unfolding operation 2310 continues).

A tensioning operation 2312 tensions the flexible membrane in contactagainst the payload base on one side of the flexible membrane in thedeployed state.

It should be understood that, in some implementation, the deployedflexible membrane is designed to be more planar, rather than lessplanar, so that electronic compensation can be made for deviations inthe “planar-ness” of the deployed flexible membrane that is, in turn,imparted to the device or devices supported by the deployed membrane. Toreduce the number and/or extent of deviations in the deployed flexiblemembrane, the number of z-folds in the undeployed flexible membrane maybe minimized, and the outer radius of the undeployed flexible membranemay be maximized. Maximizing the radius of the undeployed flexiblemembrane can result in the membrane having a tubular or cylindricalgeometric shape with a relatively hollow center when in an undeployedstate. Such an undeployed flexible membrane can collapse inward uponitself and subsequently inhibit deployment of the flexible membrane. Forexample, if such a flexible membrane is disposed within the payloadsection of a launch vehicle, the flexible nature of the flexiblemembrane may allow the flexible membrane to collapse inward,particularly during launch, and subsequently inhibit deployment of theflexible membrane.

To address this issue, one embodiment of the flexible membrane mayinclude a semi-rigid support member that is associated with the outermost panel of the membrane. The semi-rigid support member is located sothat when the flexible membrane is in an undeployed state, thesemi-rigid support member forms an inner wall of the cylindricalgeometric shape associated with the undeployed membrane. Generally, thesemi-rigid support member is significantly less flexible about an axisthat is parallel to any of the z-fold axes associated with the flexiblemembrane and, as such, prevents the undeployed flexible membrane fromcollapsing inward. The semi-rigid support member can be attached to theflexible membrane or incorporated into the flexible membrane. In anotherembodiment, two semi-rigid support members are employed, one associatedwith each of the outer-most panels of the membrane. The semi-rigidsupport members form at least a portion of one or more inner walls ofthe cylindrical geometric shape. However, in one scheme of z-folding androlling of the membrane, the use of two semi-rigid support membersreduces the extent of the folding or bending needed at one location,i.e., the two semi-rigid support members allow the radius of the bend tobe increased relative to the single semi-rigid support member approach.

The flexible membrane is further capable of being deployed such that theflexible membrane, whether a single, continuous membrane or amulti-piece membrane is continuous within the outer edge of the flexiblemembrane, i.e., there is no portion of the structure used to transitionthe flexible membrane from the undeployed state to the deployed statelocated within the boundary defined by the outer edge of the deployedmembrane. Alternatively, in multiple implementations, there is noportion of the structure used to transition the membrane that penetratesthe plane of the flexible membrane.

A deployment system used to deploy the flexible membrane from anundeployed state to a deployed state can take a number of forms.Generally, the deployment system includes a payload base and multipledeployable structures that are each supported by the payload base andengage the flexible membrane. The deployable structures can take anumber of forms, including structures that employ “carpenter's” tape,flexible rods, telescoping rods, generally one-dimensional extendablebooms, or other structures known to those skilled in the art to realizean extendable boom or truss that is employable to deploy the flexiblemembrane. In one embodiment, a number of extendable booms are realizedusing carpenter's tape to realize the longerons of the deployed boom.Each of the booms engages a location adjacent to the edge of theflexible membrane and, upon deployment, place the membrane in atensioned state in which the membrane is substantially planar.

An example system for extraterrestrial deployment of a flexible membranesurface includes a flexible membrane having a periphery and an interior.The flexible membrane is rolled about a roll axis into a cylindricalgeometric shape in an undeployed state. A payload base has extendableradial booms. Each extendable radial boom has a proximal end and adistal end with respect to the payload base, wherein the distal end ofeach extendable radial boom is attached to the periphery of the flexiblemembrane and the interior of the flexible membrane is free of attachmentto the extendable radial booms. The payload base and the extendableradial booms are positioned to one side of the flexible membrane alongthe roll axis. The extendable radial booms are configured to extendorthogonally to the roll axis from the payload base to unroll theflexible membrane about the roll axis to form the flexible membranesurface in a deployed state, wherein the roll axis is substantiallyorthogonal to the flexible membrane surface.

Another example system of any preceding system is provided, wherein theflexible membrane is further folded along a z-fold axis that isorthogonal to the roll axis in the undeployed state, wherein theextendable radial booms are further configured to unfold the flexiblemembrane along the z-fold axis into the deployed state.

Another example system of any preceding system is provided, wherein theflexible membrane is unfolded and unrolled concurrently during at leasta portion of deployment.

Another example system of any preceding system is provided, wherein theflexible membrane is expanded into the deployed state by the extendableradial booms at the one side of the flexible membrane, wherein theflexible membrane is in contact with the payload base on the one side ofthe flexible membrane in the deployed state.

Another example system of any preceding system is provided, wherein theflexible membrane is expanded into the deployed state by the extendableradial booms at the one side of the flexible membrane, wherein theflexible membrane is tensioned against the payload base on the one sideof the flexible membrane in the deployed state.

Another example system of any preceding system is provided, wherein theflexible membrane is formed from a plurality of semi-rigid panels, eachsemi-rigid panel being rollable with respect to the roll axis and beingconnected to at least one other semi-rigid panel.

Another example system of any preceding system is provided, wherein eachsemi-rigid panel has a periphery and an interior region within theperiphery and is connected to at least one other semi-rigid panel by ashear compliant connector pivotally attached to the interior region ofeach connected semi-rigid panel.

Another example system of any preceding system is provided, wherein theflexible membrane is further folded along a z-fold axis that isorthogonal to the roll axis in the undeployed state, each fold in theflexible membrane being positioned at a junction between at least twoadjacent semi-rigid panels.

Another example system of any preceding system is provided, wherein eachsemi-rigid panel is connected to at least one other semi-rigid panel bya flexible substrate fabric, each semi-rigid panel being attached to theflexible substrate fabric.

Another example system of any preceding system is provided, wherein theflexible substrate fabric is thinner and more flexible than each of thesemi-rigid panels.

Another example system of any preceding system is provided, wherein theflexible substrate fabric is continuous across the flexible membrane.

Another example system of any preceding system is provided, wherein theflexible substrate fabric is shear compliant.

Another example system of any preceding system is provided, wherein theflexible substrate fabric includes perforations along one or morez-fold.

Another example system of any preceding system is provided, wherein theflexible membrane is rolled about the roll axis in a single radialdirection in the undeployed state to form the cylindrical geometricshape.

Another example system of any preceding system is provided, wherein thecylindrical geometric shape has an interior with an interior radius, andthe flexible membrane is rolled about a small-radius loop of theflexible membrane at the interior of the cylindrical geometric shape inthe undeployed state, the small-radius loop having a radius that issmaller than the interior radius of the cylindrical geometric shape.

Another example system of any preceding system is provided, wherein thepayload base includes a synchronization pin that extends into thesmall-radius loop of the flexible membrane in the undeployed state.

Another example system of any preceding system is provided, wherein theflexible membrane includes at least one semi-rigid support member thatforms at least part of an interior surface of the cylindrical geometricshape in the undeployed state.

Another example system of any preceding system is provided, wherein thecylindrical geometric shape has an interior with an interior radius, andthe flexible membrane is rolled about two small-radius loops in theflexible membrane at the interior of the cylindrical geometric shape inthe undeployed state, the small-radius loops facing in oppositedirections and having radii that are smaller than the interior radius ofthe cylindrical geometric shape.

Another example system of any preceding system is provided, wherein thepayload base includes at least two synchronization pins, eachsynchronization pin extending into a different one of the twosmall-radius loops of the flexible membrane in the undeployed state.

Another example system of any preceding system is provided, wherein theflexible membrane includes at least two semi-rigid support members thatform at least part of an interior surface of the cylindrical geometricshape in the undeployed state.

Another example system of any preceding system is provided, furtherincluding a launch restraint cage enclosing the flexible membrane underload while in the undeployed state and configured to release theflexible membrane during deployment.

Another example system of any preceding system is provided, furtherincluding an extendable orthogonal boom being configured to extendparallel to the roll axis from the payload base in the deployed state.

Another example system of any preceding system is provided, furtherincluding one or more lanyards connecting the extendable orthogonal boomto one or more of the extendable radial booms.

Another example system of any preceding system is provided, wherein theflexible membrane is continuous within its periphery in the deployedstate.

Another example system of any preceding system is provided, wherein theflexible membrane supports one or more devices on at least one surfaceof the flexible membrane.

Another example system of any preceding system is provided, wherein thepayload base is configured to synchronize a rate of unrolling of theflexible membrane and a rate of unfolding of the flexible membrane asthe extendable radial booms extend during deployment.

An example method of extraterrestrial deployment of a flexible membranesurface includes providing a flexible membrane having a periphery and aninterior, wherein the flexible membrane is rolled about a roll axis intoa cylindrical geometric shape in an undeployed state. The example methodalso includes extending radial booms from a payload base, each radialboom having a proximal end and a distal end with respect to the payloadbase, wherein the distal end of each radial boom is attached to theperiphery of the flexible membrane and the interior of the flexiblemembrane is free of attachment to the radial booms. The payload base andthe radial booms are positioned to one side of the flexible membranealong the roll axis. The radial booms extend orthogonally to the rollaxis from the payload base. The example method also includes unrollingthe flexible membrane about the roll axis to form the flexible membranesurface in a deployed state, wherein the roll axis is substantiallyorthogonal to the flexible membrane surface.

Another example method of any preceding method is provided, wherein theflexible membrane is further folded along a z-fold axis that isorthogonal to the roll axis in the undeployed state, and the examplemethod further includes unfolding the flexible membrane along the z-foldaxis into the deployed state as the radial booms extend.

Another example method of any preceding method is provided, wherein theflexible membrane is unfolded and unrolled concurrently during at leasta portion of deployment.

Another example method of any preceding method is provided, furtherincludes synchronizing a rate of unrolling and a rate of unfolding asthe radial booms extend during deployment.

Another example method of any preceding method is provided, wherein theflexible membrane is expanded into the deployed state by the radialbooms at the one side of the flexible membrane, and further includingtensioning the flexible membrane in contact with the payload base on theone side of the flexible membrane in the deployed state.

Another example method of any preceding method is provided, wherein alaunch restraint cage encloses the flexible membrane under load while inthe undeployed state, and further including releasing the flexiblemembrane from the launch restraint cage during deployment.

Another example method of any preceding method is provided, wherein theflexible membrane is continuous within its periphery in the deployedstate.

Another example method of any preceding method is provided, wherein theflexible membrane supports one or more devices on at least one surfaceof the flexible membrane.

Another example system for extraterrestrial deployment of a flexiblemembrane surface includes a flexible membrane having a periphery and aninterior, wherein the flexible membrane is rolled about a roll axis intoa cylindrical geometric shape in an undeployed state. The example systemalso includes means for extending radial booms from a payload base, eachradial boom having a proximal end and a distal end with respect to thepayload base, wherein the distal end of each radial boom is attached tothe periphery of the flexible membrane and the interior of the flexiblemembrane is free of attachment to the radial booms, the payload base andthe radial booms being positioned to one side of the flexible membranealong the roll axis, the radial booms extending orthogonally to the rollaxis from the payload base. The example system also includes means forunrolling the flexible membrane about the roll axis to form the flexiblemembrane surface in a deployed state, wherein the roll axis issubstantially orthogonal to the flexible membrane surface.

While this specification contains many specific implementation details,these should not be construed as limitations on the scope of anyinventions or of what may be claimed, but rather as descriptions offeatures specific to particular embodiments of a particular describedtechnology. Certain features that are described in this specification inthe context of separate embodiments can also be implemented incombination in a single embodiment. Conversely, various features thatare described in the context of a single embodiment can also beimplemented in multiple embodiments separately or in any suitablesubcombination. Moreover, although features may be described above asacting in certain combinations and even initially claimed as such, oneor more features from a claimed combination can in some cases be excisedfrom the combination, and the claimed combination may be directed to asubcombination or variation of a subcombination.

Particular embodiments of the subject matter have been described. Otherembodiments are within the scope of the following claims. In some cases,the actions recited in the claims can be performed in a different orderand still achieve desirable results. In addition, the processes depictedin the accompanying figures do not necessarily require the particularorder shown, or sequential order, to achieve desirable results.

A number of implementations of the described technology have beendescribed. Nevertheless, it will be understood that variousmodifications can be made without departing from the spirit and scope ofthe recited claims.

1-35. (canceled)
 36. A system for extraterrestrial deployment of aflexible membrane surface, the system comprising: a flexible membraneincluding a periphery and an interior and adapted to be expanded from anundeployed state to a deployed state; and a payload base includingextendable booms, each extendable boom including a proximal end and adistal end with respect to the payload base, wherein the distal end ofeach extendable boom is attached to the flexible membrane, the payloadbase and the extendable booms being positioned to one side of theflexible membrane, the extendable booms being configured to increase inlength radially from the payload base and diagonally relative to az-fold axis in a direction from the payload base along which theflexible membrane is configured to expand to form the flexible membranesurface in the deployed state.
 37. The system for extraterrestrialdeployment of a flexible membrane surface of claim 36, wherein theflexible membrane surface is substantially planar in the deployed state.38. The system of claim 36, wherein the flexible membrane includessemirigid panels coupled to a shear-compliant flexible substrate fabric.39. The system of claim 36, further comprising: a launch restraint cageenclosing the flexible membrane under load while undeployed andconfigured to release the flexible membrane during deployment.
 40. Thesystem of claim 36, wherein the flexible membrane is continuous withinits periphery in the deployed state.
 41. The system of claim 36, whereinthe flexible membrane supports one or more devices on at least onesurface of the flexible membrane.
 42. The system of claim 36, whereinthe flexible membrane surface is spaced away from the payload base inthe deployed state.
 43. The system of claim 42, wherein the flexiblemembrane surface is anchored to the payload base.
 44. The system ofclaim 36, further comprising: lanyards coupling a distal end of each ofthe extendable booms to the periphery of the flexible membrane.
 45. Thesystem of claim 36, the payload base further comprising: boom portsoriented diagonally relative to the z-fold axis from which theextendable booms extend.
 46. The system of claim 45, wherein the z-foldaxis is substantially parallel to the flexible membrane surface in thedeployed state.
 47. The system of claim 36, wherein a plane defined bydistal ends of the extendable booms includes a portion of the payloadbase.
 48. The system of claim 36, further comprising: an extendableorthogonal boom configured to extend orthogonally to the z-fold axisfrom the payload base in the deployed state.
 49. The system of claim 48,further comprising: one or more lanyards connecting the extendableorthogonal boom to one or more of the extendable radial booms.
 50. Amethod of extraterrestrial deployment of a flexible membrane surface,the method comprising: providing a flexible membrane, wherein theflexible membrane is adapted to be expanded from an undeployed state toa deployed state; extending booms from a payload base by increasing thebooms in length, each boom including a proximal end and a distal endwith respect to the payload base, the booms extending orthogonally to anorthogonal axis substantially orthogonal to the flexible membranesurface and diagonally relative to a z-fold axis along which theflexible membrane is deployed; and expanding, by the operation ofextending the booms, the flexible membrane along the z-fold axis,wherein the operation of extending and the operation of expanding formthe flexible membrane surface in a deployed state.
 51. The method ofclaim 50, wherein the flexible membrane is unfolded and unrolledconcurrently during at least a portion of the deployment.
 52. The methodof claim 50, wherein a launch restraint cage encloses the flexiblemembrane under load while in the undeployed state, and furthercomprising: releasing the flexible membrane from the launch restraintcage during deployment.
 53. The method of claim 50, wherein the flexiblemembrane is continuous in the deployed state.
 54. The method of claim50, wherein the flexible membrane supports one or more devices on atleast one surface of the flexible membrane.
 55. The method of claim 50,wherein the distal end is coupled to the flexible membrane by anattachment member, the operation of expanding including pulling, by theoperation of extending the booms, the attachment member taut to form theflexible membrane surface in the deployed state.
 56. The method of claim50, further comprising: dispensing the booms from boom ports orienteddiagonally relative to the z-fold axis to cause the increase in lengthof the booms.
 57. A system for extraterrestrial deployment of a flexiblemembrane surface comprising: a flexible membrane adapted to be expandedfrom an undeployed state to a deployed state; and means for extendingbooms from a payload base by increasing the booms in length, the boomsextending from the payload base diagonally relative to an unfolding axisalong which the flexible membrane is configured to unfurl, theincreasing the booms in length unfurling the flexible membrane along theunfolding axis to form the flexible membrane surface in a deployedstate.
 58. The system of claim 36, wherein the unfolding axis is az-fold axis.